Wind turbines, in particular those in the larger sizes require effective cooling of various equipment. Cooling may be effected by a cooling circuit having the equipment as the hot spot of the circuit and a passive cooling panel as the cold spot. Such cooling panels may be arranged on the tower somewhere between the nacelle and the base platform. One or more cooling panels together with the necessary related components such as the mounting brackets, pipes, hoses etc. form a cooling panel assembly.
Service equipment outside a high wind turbine tower is commonly performed by service technicians climbing the outside of the tower with the aid of some kind of ascending devices. When descending, the cooling panel assemblies may impose a safety threat potentially causing injury to a service technician if descending at high velocity and hitting the cooling panel assembly.
In addition there is a problem with birds roosting on the cooling panel assemblies. Investigations have shown that in the neighbourhood of a platform the density of seabirds is many times higher than the density above the surrounding waters. The horizontal surfaces around the passive cooling panels are likely to be attractive roosting locations for sea birds. Several conditions contribute to that: With three cooling panel assemblies spaced around the tower, one of them will always be in the lee of the tower, i.e. sheltered from the wind. The panels will be warm in winter. The lower brackets have good weather protection, due to the panels and upper brackets. The panels are above the wave break zone. The panels are high up enough to have a good view out over the sea.
If used for roosting, then there will almost certainly be a problem with guano accumulating on the cooling panels and reducing their effectiveness, possibly substantially. Service access is sometimes very limited on offshore turbines due to weather conditions. Therefore it is highly undesirable for service technicians to have to visit a turbine to clean guano off the panels.
WO2013185767 discloses a wind tower turbine of a kind for which the present invention is applicable. The disclosure addresses the problem of shielding off cooling panels from above. Shielding is performed by a circumferential flange around the tower. For large tower this represents a waste of material and construction work, since the shielding is needed only above the cooling panels. The large part of the flange thus is not only superfluous; it also creates a restriction for vertical transports between the cooling panels. Furthermore, the cooling panels are mounted onto the flange, implying that they have to be mounted in situ.